Many industries today are fast growing and have a very short product design life. A typical example of such an industry is the computer and electronics field.
Printed circuit boards, from which computers are built, are being frequently redesigned. Thus the manufacturing lines that build these boards need to be changed often. Factory automation is one answer to this need for flexibility in production.
Many mass produced products have been built using hard or fixed automation. However, the increase in design turnover requires a more flexible solution.
The problem of printed circuit board assembly has previously been investigated using flexible automation. A typical assembly application is the insertion of nonstandard long leaded components. This problem has been partially solved by various methods where blind insertion is applied using precise fixturing of the boards while the leads are inserted using mechanical guides. Miller, D. "Robotic Assembly in Electronic Manufacturing" Robotics Today, Vol. 5, No. 6, pp. 28-32, December 1983. Sanderson, A. C., Perry, G. "Sensor-Based Robotic Assembly Systems: Research and Applications in Electronic Manufacturing", Proceedings of IEEE, Vol. 71, No. 7, pp. 856-872, July 1983. Although this method is effective, the large size of the guiding mechanism required for the leads hinders the assembly of components which are very densely packed. In addition, if it is desired to insert components with varying numbers of leads, the end effector must be changed for each class of parts. Another solution uses two television cameras, one looking at each lead from below Asano, T. et al "Vision System of an Automatic Inserter for Printed Circuit Board Assembly" Proceedings 2nd International Conference on Robot Vision and Sensory Controls, pp. 63-73, November 1982. This method works well when inserting two leaded components but would not be suitable or practical for multi-leaded parts.